Allow this to build when using a different builddir from the srcdir.

git-svn-id: svn://bind10.isc.org/svn/bind10/trunk@1658 e5f2f494-b856-4b98-b285-d166d9295462

src/bin/auth/tests/Makefile.am

@@ -1,4 +1,5 @@
-AM_CPPFLAGS = -I$(top_builddir)/src/lib -I$(top_builddir)/src/bin
+AM_CPPFLAGS = -I$(top_srcdir)/src/lib -I$(top_builddir)/src/lib
+AM_CPPFLAGS += -I$(top_builddir)/src/lib/dns -I$(top_srcdir)/src/bin
 
 CLEANFILES = *.gcno *.gcda